1. Field of the Invention
This invention relates to hand-actuated hydraulic power units, and more particularly to hand-actuated hydraulic jack structures of the type used to lift heavy weights such as automobiles and motorcycles.
2. Description of the Prior Act
One of the problems encountered in the use of a conventional hydraulic jack is that once placed for use and a weight is lifted, the jack structure cannot be moved, and since the pump assembly and pump handle assembly are fixed in position on the jack structure, the handle assembly cannot be moved at all to avoid an obstruction to pumping action of the handle, or the handle assembly can be repositioned only laboriously and only to a limited degree. Such a jack structure is depicted in U.S. Pat. No. 3,806,091 issued Apr. 23, 1974. Accordingly, it is one of the principal objects of the invention to provide a hydraulic jack structure in which the handle assembly may be rotated in a horizontal plane through an arc of about 320.degree. in relation to the associated jack structure without interrupting the pumping action.
A search of the prior art has failed to reveal a pump handle assembly that can be manufactured as a universally applicable kit for application to existing hydraulic jacks and other hydraulic power units. Accordingly, another object of the invention is to provide such a kit.
Many patents in the prior art teach the concept of detachability or flexibility between the hydraulic lifting unit or power unit and the hydraulic pump assembly. Examples of such patents include U.S. Pat. Nos. 2,927,769 and 3,081,066. Surprisingly, however, despite a diligent search, prior art patents have not been found which teach the concept of flexibility or reorientation of the pump handle assembly in relation to the pump assembly in a hydraulic power unit. Accordingly, still another object of the invention is to provide a hydraulic jack structure that incorporates this concept.
In an effort to accomplish the same purpose as the present invention, some portable hydraulic jack structures are provided with a fluid reservoir and pump assembly which as a whole unit rotates about a horizontal axis. Such a structure is taught in U.S. Pat. No. 3,370,421. Accordingly, it is another object of the invention to provide a pump assembly and pump handle assembly for a hydraulic jack structure in which the pump handle assembly rotates about a vertical axis in relation to the pump assembly.
Other patents, such as U.S. Pat. Nos. 3,286,985 and 2,903,238 teach devices in which the entire jack structure rotates in relation to the load imposed thereon. Accordingly, a still further object of the present invention is the provision of a jack structure in which only the pump handle assembly rotates in a horizontal plane in relation to the jack structure.
The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited to the embodiment illustrated, since it may be embodied in various forms within the scope of the appended claims.